Pelvis and Perineum Flashcards
Define the borders of the perineum: Anterior Posterior Anterolateral Lateral Posterolateral
Anterior: Pubic symphysis Posterior: Inferior sacrum and coccyx Anterolateral: Ischiopubic rami Lateral: Ischial tuberosities Posterolateral: Sacrotuberous ligaments
In the anatomical position:
- ) The anal triangle faces _______
- ) The urogenital triangle is oriented _______
- ) Posteroinferiorly
- ) Horizontally
- From slides, and p.244 BRS
The urogenital hiatus lies ______ in the urogenital triangle and allows passage of the _____ and ______.
Lies ANTERIORLY, and allows passage of the URETHRA and VAGINA
-Slides
What are the borders of the perineum
Anterior: Pubic symphysis Anterolateral: Ischiopubic rami Lateral: Ischial tuberosities Posterolateral: Sacrotuberous ligaments Posterior: Tip of coccyx -p.244 BRS
What two muscles make up the pelvic diaphragm (floor of the pelvis)?
Levator ani, coccygeus (ischiococcygeus)
What is the most anterior structure to pierce the pelvic diaphragm?
Urethra
What structure lies in between the urethra and the rectum? male and female
Pouch of Douglass (male), rectouterine pouch (female)
- ) What organs are said to be ABOVE the pelvic pain line?
2. ) What nerve fibers are associated with pain line (both above and below) and what carries them?
- ) Organs/portions of organs that are in contact with the peritoneum
- ) General visceral afferent fibers (pain fibers) are carried by the sympathetic nervous system. Below are carried by parasympathetic.
What artery supplies all of the external genitalia?
Internal pudendal
- ) ________ receives the deep dorsal vein of penis and vesical veins.
- ) The answer above drains into the _________.
- ) Prostatic venous plexus
- ) Internal iliac veins
* Please know, per Dr. Rich*
- ) In males, the ureter enters the bladder on the ______ aspect
- ) What structure crosses the ureter on the way to bladder
- ) Posterolateral
2. ) Ductus deferens
What gives sensory innervation to organs?
General visceral afferent: Sympathetic above pain line, parasympathetic below pain line.
Ureteric pain is usually referred to the ______ quadrant of the abdomen, especially to the _______.
IPSILATERAL LOWER QUADRANT, especially to the GROIN (inguinal region).
- ) Superior hypogastric plexus (sympathetic or parasympathetic) innervation?
- ) Pelvic splanchnics?
- ) Sympathetic
2. ) Parasympathetic
Bladder mucosa is thrown into rugae except within the ____ where it is smooth.
Trigone; near the urethral/bladder transition
What makes up the internal urethral sphincter
Circular fibers of the detrusal muscle at the neck of the bladder
List the structures that lie in relation to the following portions of the bladder:
- ) Superior (3)
- ) Inferolateral (5)
- ) Anterior (3)
- ) Peritoneum, ileum, sigmoid colon (PIS)
- ) Obturator internus, levator ani, obturator nerve, obturator artery and vein, superior vesical artery and vein
- ) Retropubic space - containing adipose tissue and veins, pubic crest
What structures lie (in relation to the bladder) 1.) posterior (4) and inferior (2) in males 2.) posterior (2), posterosuperior (2) in females.
1.) Posterior: Seminal vesicles, ampulla of ductus deferens, retrovesical pouch, ampulla of rectum. SAAD Pouch –> Sad Pouch
Inferior: Prostate, prostatic venous plexus
2.) Posterior: Cervix, anterior wall of vagina
Posterosuperior: Vesicouterine pouch, body of uterus
What arteries supply the follow portions of the bladder:
- ) Apex and superior part
- ) Fundus and neck (in males)
- ) Fundus and neck (in females)
- ) Superior vesicle arteries (branches of internal iliac)
- ) Inferior vesical arteries
- ) Vaginal arteries (branches of uterine arteries)
Define either sympathetic or para:
- ) Point (i.e. erection)
2. ) Shoot (i.e. ejac)
- ) Point = Parasympathetic
2. ) Shoot = Sympathetic
The sympathetic innervation that stimulates ejaculation simultaneously causes ________ to prevent reflux of semen into the bladder.
contraction of the internal urethral sphincter
Parasympathetic inhibition to the _______, and motor innervation to the _____ allows for urination.
- Internal urethral sphincter
- Detrusor muscle
Why is it easier for women to get UTIs?
Because of their comparitively short urethra (3-4cm)
List and describe the 3 parts of the male urethra and blood supply
- ) Prostatic urethra: Inferior vesical and rectal arteries.
- ) Membranous urethra (least dilatable part of urethra), travels through the external urethral sphincter. SHORTEST PORTION. Inferior vesical and rectal arteries
- ) Spongy urethra: Longest portion. Internal pudendal (all of external genitalia) artery via dorsal arteries of penis.
- ) Through what structure does semen enter the penis?
2. ) At what portion of the urethra?
- ) Through the ORIFICE of PROSTATIC UTRICLE
2. ) Prostatic urethra
Which part of the penis is a remnant of the fetal duct that forms the uterus in females?
Prostatic utricle
What part of the penis does the ejaculatory duct lie in?
Prostatic urethra
Describe the landmarks at the beginning of the rectum and along its course
Commences at S3 and follows the curve of the sacrum and coccyx
Which part, if any, of the rectum is BELOW the pain line?
Lower third
What structures anterior to the rectum are palpable upon prostate exam (5)? Specify male or female
- ) Prostate (males)
- ) Base of bladder
- ) Seminal vesicles (males)
- ) Ampullae of ductus deferens (males)
- ) Cervix (females)
Which arteries supply the rectum (3) and what are they branches of?
- ) Superior rectal (IMA)
- ) Middle rectal (internal iliac)
- ) Inferior rectal (internal pudendal)
Which venous systems are the superior, middle, and inferior rectal veins a part of?
Superior = portal
Middle and inferior = systemic
The _____ becomes the ductus deferens
Tail of the epididymis
When the ____ joins the _____, they form the ejaculatory duct, which opens into the _____
- Ductus deferens joins the seminal vesicle
- Opens into the prostatic urethra
What connects the vesicular/prostatic venous plexus to the internal vertebral plexus? Why is this important?
Batson’s plexus (valveless veins): Important because this is how cancers from pelvic area and chest travel to vertebral area and brain.
What is the round ligament embryologically
Umbilical vein
What does the prostate surround?
It surrounds the prostatic urethra (neck of the bladder)
Which lobe of the prostate is palpable on a rectal exam?
Inferoposterior (lower posterior) lobe
A tumor of what structure (besides prostate) can increase PSA?
Bulbourethral
Where does the perineal body of the central tendon lie in males and females?
Anterior to the anal canal, posterior to the vesibule (in females) and penis (in males).
What is Buck’s fascia a continuation of?
The deep perineal fascia
What structure is cut during a median episiotomy?
Central perineal tendon
- ) What is the structure that divides the anal canal into superior and inferior portions? What makes up this structure?
- ) What are the embryologic tissue that formed the superior and inferior anal canal?
1.) Pectinate (or dentate) line, made up of the inferior end of the anal valves.
2.) Superior = embryonic ectoderm (hindgut)
Inferior = ectoderm (proctodeum)
Concerning the two anal sphincters, which is voluntary and which is involuntary?
External = voluntary Internal = involuntary
The internal anal sphincter is made up of a _____ muscle whose contraction is stimulated by _____ fibers from the _____ and ____ plexuses.
Circular muscle, sympathetic fibers from the superior rectal (periarterial) and hypogastric plexuses.
What is the blood supply of the anal canal ABOVE the pectinate line? Below?
Above: Superior rectal artery
Below: Inferior rectal artery
What lymph nodes would be enlarged by an anal abscess below the pectinate line? Above?
Below: Superficial inguinal lymph nodes
Above: Internal and common iliac and lumbar nodes (INTERNAL ILIAC)
What is venous drainage for the anal canal above and below pectinate line?
Above: Internal venous plexus –> to SUPERIOR RECTAL VEIN and PORTAL SYSTEM
Below: Internal venous plexus –> INFERIOR RECTAL VEINS and CAVAL SYSTEM.
What provides pain sensation to the anal canal BELOW the pectinate line?
Pudendal nerve (somatic)
- ) What are ischioanal fossae?
2. ) How/where do they communicate with one another?
- ) Fat-filled, wedge-shaped recesses on either side of anal canal
- ) Communicate with each other posteriorly over the anococcygeal ligament.
What/where is the Alcock canal and what does it contain?
- Alcock’s (pudendal) canal is a fascial canal formed by a split in the obturator internus fascia.
- Lies in the LATERAL ASPECT of the ISCHIOANAL FOSSA
- It contains: Internal pudendal vessels, pudendal nerve and perineal nerve. (Supplies most of genitalia and perineum)
What is the nerve supply for the external anal sphincter?
Inferior rectal nerve (branch of pudendal nerve)
What supplies innervation to the scrotum?
Posterior: Perineal nerve (from pudendal)
Anterior: Anterior scrotal/labial nerve –> terminal branches of ilioinguinal nerve.
What structures does the perineal nerve supply?
“Perineum and BESS”
Bulb of penis, external sphincter urethrae, superficial and deep transverse perineal muscles, skin of perineum.
- ) Where can blood from a ruptured urethra go in males?
2. ) Where can it NOT go? Why?
- ) Can go into ABDOMEN and SCROTUM.
- ) Cannot go into ANAL TRIANGLE (because Colle’s fascia is attached to perineal membrane) or THIGH (because of attachment to fascia lata).
- ) Where is the superficial perineal space?
2. ) What are its contents (4)?
- ) [Moore p.404 –> “A potential space found between the perineal fascia (Colles’ Fascia) and the perineal membrane (i.e. inferior fascia of the urogenital diaphragm), bounded laterally by the ischiopubic rami.”]
- (Dr. Rich) –> Found between Colles’ fascia (deep to) and the inferior fascia of the urogenital diaphragm, represented in this image as the perineal membrane. - ) Bulb of the penis, bulbosongiosus (covering bulb of penis), ischiocavernosus muscles (covering the erectile crura tissue), and superficial transverse perineal muscles, deep perineal branches of the internal pudendal vessels and nerves.
p. 404 Moore
The superior fascia of the UG diaphragm is is continuous with the ___________.
Inferior fascia of the pelvic diaphragm
What are the contents of the male deep perineal pouch?
- ) Intermediate/membranous part of urethra (narrowest part)
- ) Deep transverse perineal muscle
- ) Sphincter urethrae
- ) Bulbourethral glands
- ) Branches of the internal pudendal vessels and pudendal nerve
- p.247 BRS
The perineal membrane is made up of what?
Inferior fascia of the UG diaphragm
What are the layers of the UG triangle from superficial to deep (9)?
- ) Skin
- ) Superficial (Camper’s) Fascia
- ) Colles’ Fascia
- ) Superficial perineal pouch/space (bulbourethral glands, ischiocavernosus muscle, bulbospongeosus muscle, blood vessels and nerves)
- ) Perineal membrane (inferior fascia of UG diaphragm)
- ) UG diaphragm (sphincter urethrae, deep transverse perineal muscle)
- ) Superior fascia of UG diaphragm
- ) Pelvic diaphragm
- ) Superior fascia of pelvic diaphragm
* MATCH UP WITH LAYERS @ 11:16 lecture 34b*
What muscles make up the UG diaphragm (2)?
- ) Sphincter urethrae
2. ) Deep transverse perineal muscle
- ) What gland does the superficial perineal pouch contain in females?
- ) What is the analogous structure in males? Where is it?
- ) Greater vestibular gland
- ) Cowper’s gland in the SUPERFICIAL PERINEAL POUCH
* EXAM QUESTIONS*
In females, what does the deep perineal pouch contain? How is this different in males?
Mass of smooth muscle (in place of deep transverse perineal muscles in males) and UG diaphragm
What is an alternate name for the deep perineal fascia?
Gallaudet’s Fascia
What is the superior and inferior fascia of the deep pouch?
Superior: Inferior fascia of the pelvic diaphragm
Inferior (floor): Strong perineal membrane
In both males and females, the musculature of the urogenital sphincter is oriented ______ to the _______, rather than lying in a plane _______ to it.
Oriented PERPENDICULAR to the PERINEAL MEMBRANE, rather than lying in a plane PARALLEL to it.
What are the two parts of the clitoris from anterior to posterior?
Glans of clitoris –> Frenulum of clitoris
A cyst of the greater vestibular gland in women causes swelling of what?
Swelling of labia
What is the name of the spot where the two labia minora meet?
Frenulum of labia minora
What is the mons pubis?
Fatty tissue lying anterior to the pubic symphysis and superior pubic rami
What is the vestibule of the vagina?
The area lying in between the two labia minora, it contains the vaginal and urethral opening.
What provides innervation for the female external genitalia and what are they branches of (3)?
- ) Anterior labial nerves from ilioinguinal nerve
- ) Perineal branch from posterior femoral cutaneous nerve
- ) Posterior labial nerves from pudendal nerve
In order to perform surgery on female pelvis/genitals, what nerve should be blocked and what bony landmark is used to locate it?
- Pudendal nerve
- Landmark is ISCHIAL SPINE
Concerning a carcinoma of the vulva:
- ) Where does metastasis usually occur to?
- ) What is the origin of most vulvar adenocarcinomas?
- ) Inguinal lymph nodes
2. ) Greater vestibular gland
What is a Bartholin cyst?
Cystic swelling of the greater vestibular (Bartholin’s) gland. Occurs when gland is infected or duct is enlarged.
What is vaginismus, i.e. what becomes distended and what muscles are involved?
An emotional (psychosomatic disorder) in which the initial distention of the bulbospongiosus and transverse perineal muscles are thought to trigger the involuntary spasms of the perivaginal and levator ani muscles of vaginismus.
-Can cause dyspareunia and prevent vaginal entry for intercourse.
The body of the penis is anchored in the ______, and is attached to the ________.
Superficial perineal space (pouch), and is attached to the PERINEAL MEMBRANE
The glans of the penis is the ________.
Distal expansion of the corpus spongiusom
The root of the penis is formed by _______ (2)
- ) Bulb
2. ) Crura x2
What covers the bulb of the penis?
Bulbospongiosus muscle
What covers the crura of the penis?
Ischiocavernosus muscle
List the tissue layers of the penis from superficial to deep
Skin, subcutaneous tissue, deep fascia of the penis (Buck’s fascia), Tunica albuginea.
Between which tissue layers of the penis do vessels and nerves run?
On the dorsum of the penis between:
- ) Skin and deep fascia
- ) Deep fascia and tunica albuginea
What provides innervation to the proximal shaft of the penis?
Ilioinguinal nerve
What is the blood supply for the erectile tissue of the penis?
Highly coiled branches of HELICINE ARTERIES
What arteries run on either side of the deep dorsal vein of penis? Where do they arise from?
Dorsal arteries of the penis from internal pudendal arteries.
What runs within the center of the corpora cavernosa?
Deep arteries from internal pudendal arteries.
What is the blood supply for the skin of the penis? Arise from where?
External pudendal arteries (branch of femoral artery)
Where do veins from the penis drain (2)?
- ) Deep dorsal vein drains to internal iliac/pudendal veins
- ) Superficial dorsal vein drains to external pudendal
Where do lymphatics from penis drain?
Superficial inguinal lymph nodes
What is hypospadias?
When the external urethral orifice is on the ventral aspect of the penis, or on the body of the penis (penile hypospadias)
Ureteric pain is usually referred to where?
the ipsilateral lower quadrant of the abdomen, especially to the groin
p.363
The rectosigmoid junction lies in relation to which vertebral level?
anterior to S3.
What is the innervation (and its vertebral level) to the external anal sphincter?
Innervation supplied mainly by S4 through the inferior rectal nerve.
p.413